Field of the Invention
This invention relates to the field of ring binders and adapters for same.
Background Art
Choral music, such as used by choirs and choruses, consists of sheets folded in the middle. The music could consist of one sheet or multiple sheets folded and assembled at the fold. Those comprising more than one sheet are often stapled along the fold. Such music is frequently held in binders or folders that can hold several selections of music, each of which can be opened, selection by selection and page by page as it is sung. A common three-ring binder is often used for holding the music, and that works well when the music has been punched with three holes. However, some organizations do not permit their music to be punched, especially those selections borrowed from other choral groups or music libraries. In these cases a separate adapter is required to hold the music to the three rings, or a folder other than a three-ring binder is used, leaving the music free to slide out during a concert.
One common adapter used to hold music in a typical three-ring binder is made from a narrow rectangle of thin plastic having three holes along one edge adjacent a long slot through which half the pages of the music may be slid, across to their fold. Either stapled or simply folded music is used with this adapter in the same manner, and the adapter works well for storage or general use, but is somewhat inadequate when the music is being presented in concert. Because this adapter does not clamp the music sheets within the slot it allows unstapled sheets of music to separate and become displaced from the fold. Misaligned folds hinder turning of the pages, a particular problem in music where sections of the score are repeated, requiring abrupt turning of pages backward and forward. Moreover, because the music is free to slide within the adapter slot, even the adapter itself can become misaligned with the fold line at the centerfold.
Similar problems exist with a metal wire adapter as taught by Squire et al. (U.S. Pat. No. 4,645,237), where a free-moving wire retainer is provided for each selection, but where again no provision is made to prevent slipping of sheets out from within the retainer.
There are also purpose-built music holding folders, having means incorporated to serve the same objectives as above. Some of them work well but have shortcomings either because the material they use makes them expensive or has a relatively short service life. Others are not easy to use and do not lend themselves well to changing the order of the music, especially when the change needs to be made in a hurry. Still others are limited by the number of musical selections they can hold. Examples include Clarke (U.S. Pat. No. 71,703) and Girard (U.S. Pat. No. 6,254,135) where a parallel series of elastic strands are employed, each strand to rest within the fold, yet each adjacent strand obstructing the free rotation of sheets that is normally necessary.